A composite image of Mets pitchers Matt Harvey, left, and Zack Wheeler, right, who will pitch for the team on Tuesday. Photo Credit: Jim McIsaac/Alejandra Villa

It's official: Zack Wheeler will make his major-league debut on Tuesday night in the second half of a day-night doubleheader against the Braves in Atlanta.

Matt Harvey will start the 1:10 p.m. opener, which is a makeup of a May 4 rainout. Wheeler will start the 7:10 p.m. nightcap with family and friends in the stands at Turner Field; he lives about 30 miles away in Dallas, Ga.

That the Mets' young ace (Harvey) and their top prospect (Wheeler) will be pitching on the same day will be an event in a disappointing season.

Manager Terry Collins said Friday night that the Mets decided to pitch Wheeler in the second game to give the 23-year-old righthander a chance to stay in his normal night-game routine.

"We just said we thought it would be better for him and more comfortable for him to continue on what he's used to doing," Collins said. "And that's pitching at night. The night game. Give him a chance to get to the ballpark at his regular time, go through his regular routine without having to get there in the morning at 9 o'clock and not maybe have enough time to get himself prepared. That came into it more than anything."

It was suggested to Collins that Wheeler could face less pressure if he debuted in the day game -- which as a makeup game on a workday will likely be sparsely attended. But Collins said that wasn't a consideration.

"You're not going to take the pressure away from this guy," Collins said. "You could pitch him in a boneyard -- you're not going to take the pressure off this guy . . . It doesn't matter if it's at noon or if it's at 1 or if it's at 7 . . . There's going to be a lot of heat on him. He's going to put it on himself. I just thought put him where he's the most comfortable and that would be pitching in the second game."

Wheeler, on an 85-pitch limit, threw a gem in his final Triple-A start for Las Vegas on Thursday night. He allowed one hit -- a solo home run -- in 5 2/3 innings against Tacoma with two walks and seven strikeouts. In 13 starts for Las Vegas, Wheeler was 4-2 with a 3.93 ERA. In 68 2/3 innings, he allowed 61 hits, walked 27 and struck out 73.

"I'm looking forward to [moving up]," Wheeler told reporters after Thursday's outing. "It's going to be a lot of fun."

Wheeler, on his verified Twitter account, Friday night posted: "Thanks everybody for the support along this road to the show. It's an honor to be called up by the @Mets. Big thanks to my family and friends.

"And the great fans of NY. It's going to be very exciting for many years to come. Thanks again everybody."

Collins indicated that Harvey will pitch on June 23 in Philadelphia, which would slot Wheeler's second start for June 25 at the Chicago White Sox. That puts Wheeler in line for a Citi Field debut on June 30 vs. Washington (or July 1 vs. Arizona if the Mets stay with a six-man rotation, as Collins says they plan to do for at least two turns once Wheeler is promoted).

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